docs: def parse_text_data(lines_or_path, delimiter=os.linesep):
      """
      Interpret input argument as lines of data. This is intended to support
      multiple input argument types to core model constructors.
  
      :param str | collections.Iterable lines_or_path:
      :param str delimiter: line separator used when parsing a raw string that's
          not a file
      :return collections.Iterable: lines of text data
      :raises ValueError: if primary data argument is neither a string nor
          another iterable
      """
  
      if os.path.isfile(lines_or_path):
          with open(lines_or_path, 'r') as f:
              return f.readlines()
      else:
          _LOGGER.debug("Not a file: '{}'".format(lines_or_path))
  
      if isinstance(lines_or_path, str):
          return lines_or_path.split(delimiter)
      elif isinstance(lines_or_path, Iterable):
          return lines_or_path
      else:
          raise ValueError("Unable to parse as data lines {} ({})".
                           format(lines_or_path, type(lines_or_path)))